﻿(function (window) {
  //兼容
  window.URL = window.URL || window.webkitURL;
  navigator.getUserMedia =
    navigator.getUserMedia ||
    navigator.webkitGetUserMedia ||
    navigator.mozGetUserMedia ||
    navigator.msGetUserMedia;

  var HZRecorder = function (stream, config) {
    console.log(stream, config)
    config = config || {};
    config.sampleBits = config.sampleBits || 8; //采样数位 8, 16
    config.sampleRate = config.sampleRate || 44100 / 6; //采样率(1/6 44100)

    var context = new(window.webkitAudioContext || window.AudioContext)();
    var audioInput = context.createMediaStreamSource(stream);
    var createScript =
      context.createScriptProcessor || context.createJavaScriptNode;
    var recorder = createScript.apply(context, [4096, 1, 1]);

    var audioData = {
      size: 0, //录音文件长度
      buffer: [], //录音缓存
      inputSampleRate: context.sampleRate, //输入采样率
      inputSampleBits: 16, //输入采样数位 8, 16
      outputSampleRate: config.sampleRate, //输出采样率
      oututSampleBits: config.sampleBits, //输出采样数位 8, 16
      input: function (data) {
        this.buffer.push(new Float32Array(data));
        this.size += data.length;
      },
      compress: function () {
        //合并压缩
        //合并
        var data = new Float32Array(this.size);
        var offset = 0;
        for (var i = 0; i < this.buffer.length; i++) {
          data.set(this.buffer[i], offset);
          offset += this.buffer[i].length;
        }
        //压缩
        var compression = parseInt(
          this.inputSampleRate / this.outputSampleRate
        );
        var length = data.length / compression;
        var result = new Float32Array(length);
        var index = 0,
          j = 0;
        while (index < length) {
          result[index] = data[j];
          j += compression;
          index++;
        }
        return result;
      },
      encodeWAV: function () {
        var sampleRate = Math.min(this.inputSampleRate, this.outputSampleRate);
        var sampleBits = Math.min(this.inputSampleBits, this.oututSampleBits);
        var bytes = this.compress();
        var dataLength = bytes.length * (sampleBits / 8);
        var buffer = new ArrayBuffer(44 + dataLength);
        var data = new DataView(buffer);

        var channelCount = 1; //单声道
        var offset = 0;

        var writeString = function (str) {
          for (var i = 0; i < str.length; i++) {
            data.setUint8(offset + i, str.charCodeAt(i));
          }
        };

        // 资源交换文件标识符
        writeString("RIFF");
        offset += 4;
        // 下个地址开始到文件尾总字节数,即文件大小-8
        data.setUint32(offset, 36 + dataLength, true);
        offset += 4;
        // WAV文件标志
        writeString("WAVE");
        offset += 4;
        // 波形格式标志
        writeString("fmt ");
        offset += 4;
        // 过滤字节,一般为 0x10 = 16
        data.setUint32(offset, 16, true);
        offset += 4;
        // 格式类别 (PCM形式采样数据)
        data.setUint16(offset, 1, true);
        offset += 2;
        // 通道数
        data.setUint16(offset, channelCount, true);
        offset += 2;
        // 采样率,每秒样本数,表示每个通道的播放速度
        data.setUint32(offset, sampleRate, true);
        offset += 4;
        // 波形数据传输率 (每秒平均字节数) 单声道×每秒数据位数×每样本数据位/8
        data.setUint32(
          offset,
          channelCount * sampleRate * (sampleBits / 8),
          true
        );
        offset += 4;
        // 快数据调整数 采样一次占用字节数 单声道×每样本的数据位数/8
        data.setUint16(offset, channelCount * (sampleBits / 8), true);
        offset += 2;
        // 每样本数据位数
        data.setUint16(offset, sampleBits, true);
        offset += 2;
        // 数据标识符
        writeString("data");
        offset += 4;
        // 采样数据总数,即数据总大小-44
        data.setUint32(offset, dataLength, true);
        offset += 4;
        // 写入采样数据
        if (sampleBits === 8) {
          for (var i = 0; i < bytes.length; i++, offset++) {
            var s = Math.max(-1, Math.min(1, bytes[i]));
            var val = s < 0 ? s * 0x8000 : s * 0x7fff;
            val = parseInt(255 / (65535 / (val + 32768)));
            data.setInt8(offset, val, true);
          }
        } else {
          for (var i = 0; i < bytes.length; i++, offset += 2) {
            var s = Math.max(-1, Math.min(1, bytes[i]));
            data.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7fff, true);
          }
        }

        return new Blob([data], {
          type: "audio/mp3"
        });
      }
    };

    //开始录音
    this.start = function () {
      audioInput.connect(recorder);
      recorder.connect(context.destination);
    };

    //停止
    this.stop = function () {
      recorder.disconnect();
    };

    //获取音频文件
    this.getBlob = function () {
      this.stop();
      console.log(audioData.encodeWAV())
      return audioData.encodeWAV();
    };

    //回放
    this.play = function (audio) {
      console.log(this.getBlob())
      audio.src = window.URL.createObjectURL(this.getBlob());
    };

    //上传
    this.upload = function (url, callback) {
      var fd = new FormData();
      fd.append("audioData", this.getBlob());
      var xhr = new XMLHttpRequest();
      if (callback) {
        xhr.upload.addEventListener(
          "progress",
          function (e) {
            callback("uploading", e);
          },
          false
        );
        xhr.addEventListener(
          "load",
          function (e) {
            callback("ok", e);
          },
          false
        );
        xhr.addEventListener(
          "error",
          function (e) {
            callback("error", e);
          },
          false
        );
        xhr.addEventListener(
          "abort",
          function (e) {
            callback("cancel", e);
          },
          false
        );
      }
      xhr.open("POST", url);
      xhr.send(fd);
    };

    //音频采集
    recorder.onaudioprocess = function (e) {
      audioData.input(e.inputBuffer.getChannelData(0));
      //record(e.inputBuffer.getChannelData(0));
    };
  };
  //抛出异常
  HZRecorder.throwError = function (message) {
    alert(message);
    throw new function () {
      this.toString = function () {
        return message;
      };
    }();
  };
  //是否支持录音
  HZRecorder.canRecording = navigator.getUserMedia != null;
  //获取录音机
  HZRecorder.get = function (callback, config) {
    if (callback) {
      if (navigator.getUserMedia) {
        navigator.getUserMedia({
            audio: true
          }, //只启用音频
          function (stream) {
            var rec = new HZRecorder(stream, config);
            console.log(rec)
            callback(rec);
          },
          function (error) {
            switch (error.code || error.name) {
              case "PERMISSION_DENIED":
              case "PermissionDeniedError":
                HZRecorder.throwError("用户拒绝提供信息。");
                break;
              case "NOT_SUPPORTED_ERROR":
              case "NotSupportedError":
                HZRecorder.throwError("浏览器不支持硬件设备。");
                break;
              case "MANDATORY_UNSATISFIED_ERROR":
              case "MandatoryUnsatisfiedError":
                HZRecorder.throwError("无法发现指定的硬件设备。");
                break;
              default:
                HZRecorder.throwError(
                  "无法打开麦克风。异常信息:" + (error.code || error.name)
                );
                break;
            }
          }
        );
      } else {
        HZRecorder.throwErr("当前浏览器不支持录音功能。");
        return;
      }
    }
  };

  window.HZRecorder = HZRecorder;
})(window);